1. Field of the Invention
The invention relates to a method and means for cavity mining materials from a subsurface deposit.
2. Prior Art
The most common techniques for removing coal from the ground are by strip mining, in which the coal is dug out of the ground by hydraulic or mechanical means, and underground mining, in which slurry mining (U.S. Pat. No. 3,260,548), room and pillar, or long-wall techniques are employed. In slurry mining, hydraulic apparatus is used to direct pressurized water at the coal seam to disaggregate the coal and form a slurry which is then pumped out of the mine. The present invention provides an improvement in this type of coal mining.